Taser use: get the data

Newly released figures reveal the frequency of British police officers firing Tasers at suspects' chests, despite explicit warnings from the weapon's manufacturer over the dangers of causing cardiac arrest. Which forces are included and what did we find?

Contrary to medical advice and manufacturer's warnings, UK police are firing Taser stun guns at the chests of suspects in the majority of cases, according to newly released data.

There is evidence to suggest that shots to the chest are more dangerous because they can result in cardiac arrest. The manufacturer's own training guidance states: "When possible, avoid targeting the frontal chest area near the heart to reduce the risk of potential serious injury or death."

57% of shots to the chest

Of the 45 UK police forces that were asked about taser gun use, 18 replied with statistics. The original freedom of information request included questions about the total number of uses and the number of times that an individual had been hit in the chest area by a Taser weapon between 2009 and 2012.

On average, 57% of all Taser discharges resulted in an individual being hit in the chest. There were however large differences between police forces - from 100% of three Taser uses by City of London police, to 17% of the 24 occasions that Suffolk police used the weapon.

In forces such as Lancashire and West Mercia, use of Tasers was far more prevalent with 186 and 138 discharges respectively.

The data is also complicated by the fact that different forces collect different data about Taser incidents. Cumbria's police force were only able to supply data for 2010-12, as they no longer hold Taser figures dating from 2009. In the case of South Wales, the police force also did not have information for 2009, and were only able to record hits to the 'torso' rather than the chest specifically.

Possible factors

Police say the weapons are an invaluable means of incapacitating a suspect without resorting to using firearms. But what drives the way they are used? Simon Chesterman, deputy chief constable of West Mercia police, where there were 62 incidents of a Taser being fired to the chest, said:

When you've got a violent assailant who is facing you, coming towards you and you have to make a split second decision whether to use Taser or not the chances are that clearly you're going to aim for the torso

We looked at the latest official figures on violent crime per 1,000 residents to see if this was more prevalent in the police forces that used the weapons most.

Correlation shown by Statwing

The correlation between shots being fired to the chest and violent crime rates is weak (shown left) - as is the link between total Taser uses and violent crime (right). The data has to be treated with caution because with such a small sample size (just 31% of the UK's police forces have comparable information) it is hard to reach any conclusions.

The relationship between Taser use and assaults on police officers appears to be clearer. Though we could only find numbers on assaults in England and Wales in 2009-10 (the Taser data covers 2009-12) there is an indication that where officers are more likely to be attacked, they are also more likely to use Tasers. This was true whether the Tasers were fired to the chest or elsewhere on the body, and whether the injury sustained by the officer was minor or serious.

The relationship was clearest when looking at overall Taser use and assaults on police officers that resulted in no or only minor injuries, as shown below.

Correlation shown by Statwing

In Lancashire, 303 police officers were assaulted in 2009/10 - the highest of any force we looked at. Lancashire was also the police force in England and Wales with the highest overall use of Tasers (186) and the highest use of Tasers to the chest (120). South Wales also came second in terms of prevalence of Taser use and second on the number of police officers to be assaulted.

This by no means fully explains Taser trends - training and culture are likely to play a huge role. Anomalies demonstrate this - in West Mercia, visibly different in the graph above, there were 138 Taser uses, of which 62 were to the chest while a total of 91 officers were assaulted in 2009/10 - a figure far lower than many other police forces.